Which hardware for my project?

Hello together,

my Home Assistant is running as Virtual Machine on my Synology NAS.
I have already bought a touch display which I want to use as a display for HA.
I also use Homematic IP. Because of that, that I want to change to Raspberrymatic, my idea was to buy a raspberry (Pi 4?) + funk module and put it behind the display an use as display for the Home Assistant and at the same time as Homematic access point.

Or the better way would be to buy a weaker raspberry for the display and use my Synology for the access point of Homematic IP? Of course all should work with Home Assistant.

One problem which I see is, that my NAS in cellar is.

I hope You can give me some tipps which way would be the best. Thank You